US Bridges

SR 203 over Drainage Overflow

Poor

Snohomish County, Washington · 4.1 N King CO · Structure no. 0004825B0000000

Built
1954
71 years old
Condition
Poor
inspected July 2023
Type
Slab
Concrete Continuous
Length
89 ft
3 main spans
Daily traffic
12,132
2023 count
Owner
State
State Highway Agency

About this bridge

SR 203 over Drainage Overflow is a concrete continuous slab carrying SR 203 over Drainage Overflow in Snohomish County, Washington. It was built in 1954, so it is 71 years old, older than the Washington average of 49.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 3 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

It carries about 12,132 vehicles a day, roughly 9% of them trucks, projected to reach 17,497 by 2039. The structure is 89 ft (27.1 m) long and 34 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesSR 203
CrossesDrainage Overflow
Location4.1 N King CO
RouteState Highway 203
CountySnohomish County
StateWashington
Coordinates47.82881, -121.97028
Functional classRural Minor Arterial

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Deck3 SeriousLoss of section, deterioration, spalling or scour have seriously affected primary structural components.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating32.5 US tons
Inventory rating25 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 15
Structure length89 ft (27.1 m)
Longest span33 ft (10.1 m)
Deck width34 ft (10.4 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic12,132 (2023)
Projected traffic17,497 by 2039
Trucks9%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed5 mi (8 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$1.7 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was SR 203 over Drainage Overflow built?

It was built in 1954, making it 71 years old in 2025.

What condition is SR 203 over Drainage Overflow in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in July 2023.

How much traffic does SR 203 over Drainage Overflow carry?

About 12,132 vehicles per day (2023 count), of which roughly 9% are trucks.

How long is SR 203 over Drainage Overflow?

The structure is 89 ft (27.1 m) long with a longest span of 33 ft (10.1 m) and a deck 34 ft wide.

Who owns SR 203 over Drainage Overflow?

It is owned by the State Highway Agency.